Mac Pro - Blue Screen Stall and Dead Firewire

First post, hoping I can get some help or insight or a point in the right direction for something I may have not tried with my current problem. I am creating this post in two segments, the first part "preface" is for the edification to those that are searching for a solution to my first problem which took me days to figure out. The second part is my current problem that I'm hoping there is a non-service based solution to.

Preface
A little while ago my Mac Pro early 2008 model started taking excessively long to boot (10+ minutes). I finally got around to investigating and trying to solve the problem. The symptoms were: normal boot sequence up until the blue screen (usually only up for a few seconds), then hang for 10 minutes before showing the login screen. I found a plethora of articles describing the problem I was having and indicated it was anything from a bogus update to outdated software (APE), etc. None of these problems were relevant to my scenario, especially after I performed a complete reinstall of the OS. Finally I decided to pay very close attention to the output in verbose mode instead of looking at the console log. In verbose mode the last line before the blue screen was a timeout with one of the IOFirewire kexts initializations.

Shooting in the dark, I decided to remove the kext files relating to IOFirewire out of my /Library/Extensions folder and to my surprise booting went back to a normal timeframe of less than 30 seconds. As this was a fresh install I realized something else must be wrong with my Mac Pro than just software/driver corruption.

Current Problem
Ok, so my initial issue has been solved, but now I'm going down another rabbit hole. I've almost never used my firewire ports (so frying them with hot swaps is not plausible), but they certainly do not work (especially when no drivers are loaded for them). Even if I let the 10 minute boot cycle go, firewire shows "no information" in the devices pane.

Here are the troubleshooting steps I have taken so far.

I have attempted to reset the PRAM with the <command>-<option>-<p>-<r> combo on boot.

I have ran Apple Hardware Test (which came up perfectly clean which gives me small hope).

I have booted in Firewire Target Mode (paired machine did not see my mac pro as a hdd, though I'm not convinced I did this right and I did not test all available firewire ports).

Reinstalled OS X fresh, twice.

Powered off the machine and unplugged all devices and Power cord, left unplugged for 15+ minutes.

Powered down with Power button and left pressed in until the flashed several times with a unique beeping sound then let it boot normally.

I'm keeping up hope that there is something I have not tried to resurrect my firewire... but things are starting to look grim.

Considering the consensus may be that the firewire bus is dead, I have purchased a firewire card as a replacement... the problem with this solution is that enabling the firewire kexts brings back the 10 minute boot times... I'm hoping there is a way to disable only the internal firewire bus.

I at least hope the first part of this post was helpful to people whom may have a similar issue that, like me, was been unable to dig something up through google.

Update: I've confirmed about as much as one can confirm that the internal firewire is kentucky fried. I got a pcie card to work as expected, but to use it in osx I still have to wait the 10 minute boot times... unfortunate. New logic board for me.

Hi I just had the same problem with a long boot on my Mac Pro (Early 2008).

Just checked system profile and the firewire bus is indeed not working.
That explains why my hard drive stopped working via Firewire 800 the other day - just had assumed it was a lead and was using it via USB.....